#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/cdev.h>
#include <linux/device.h>
#include <linux/ide.h>
#include <asm/mach/map.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#define LEDDEV_CNT         1
#define LEDDEV_NAME        "platled"
#define LEDON               1
#define LEDOFF              0
 
static void __iomem  *IMX6U_CCM_CCGR1;             
static void __iomem  *SW_MUX_GPIO1_IO03;     
static void __iomem  *SW_PAD_GPIO1_IO03;   
static void __iomem  *GPIO1_DR;             
static void __iomem  *GPIO1_GDIR;             


struct led_dev{
    dev_t devid;
    struct cdev cdev;
    struct class *class;
    struct device *device;
    int major;
    int minor;
    struct device_node  *nd;
    int led_gpio;
};

struct led_dev leddev;

void led0_switch(u8 sta)
{
    u32 val =0;

    if(sta == LEDON){
        val = readl(GPIO1_DR);
        val &= ~(1 << 3);
        writel(val,GPIO1_DR);
    }
    else if(sta == LEDOFF)
    {
        val = readl(GPIO1_DR);
        val |= (1 << 3);
        writel(val,GPIO1_DR); 
    }
}

static int led_open(struct inode *inode, struct file *filp)
{
    filp->private_data = &leddev;
    return 0;
}

static ssize_t led_write(struct file *filp, const char __user *buf, size_t cnt, loff_t *offt)
{
    int retvalue;
    unsigned char databuf[1];
    unsigned char ledstat;

    retvalue = copy_from_user(databuf,buf,cnt);
    if(retvalue < 0){
        printk("kernel write failed!\r\n");
        return -EINVAL;
    }

    ledstat = databuf[0];
    
    if(ledstat == LEDON){
        led0_switch(LEDON);
    }else if(ledstat == LEDOFF){
        led0_switch(LEDOFF);
    }
    return 0;
}

static struct file_operations led_fops = {
    .owner = THIS_MODULE,
    .open  = led_open,
    .write = led_write,
};

static int led_probe(struct platform_device *dev)
{
    int i = 0;
    int ressize[5];
    u32 val;
    struct resource *ledsource[5];

    printk("led driver and device has matched!\r\n");
    for(i = 0; i < 5 ; i++){
        ledsource[i] = platform_get_resource(dev,IORESOURCE_MEM,i);
        if(!ledsource[i]){
            dev_err(&dev->dev,"No MEM resource for always on\n");
            return -ENXIO;
        }
        ressize[i] = resource_size(ledsource[i]);
    }

    IMX6U_CCM_CCGR1 = ioremap(ledsource[0]->start, ressize[0]);
    SW_MUX_GPIO1_IO03 = ioremap(ledsource[1]->start, ressize[1]);
  	SW_PAD_GPIO1_IO03 = ioremap(ledsource[2]->start, ressize[2]);
	GPIO1_DR = ioremap(ledsource[3]->start, ressize[3]);
	GPIO1_GDIR = ioremap(ledsource[4]->start, ressize[4]);

	val = readl(IMX6U_CCM_CCGR1);
	val &= ~(3 << 26);				/* 清除以前的设置 */
	val |= (3 << 26);				/* 设置新值 */
	writel(val, IMX6U_CCM_CCGR1);

	/* 设置GPIO1_IO03复用功能，将其复用为GPIO1_IO03 */
	writel(5, SW_MUX_GPIO1_IO03);
	writel(0x10B0, SW_PAD_GPIO1_IO03);

	/* 设置GPIO1_IO03为输出功能 */
	val = readl(GPIO1_GDIR);
	val &= ~(1 << 3);			/* 清除以前的设置 */
	val |= (1 << 3);			/* 设置为输出 */
	writel(val, GPIO1_GDIR);

	/* 默认关闭LED1 */
	val = readl(GPIO1_DR);
	val |= (1 << 3) ;	
	writel(val, GPIO1_DR);

    if(leddev.major){
        leddev.devid = MKDEV(leddev.major,0);
        register_chrdev_region(leddev.devid,LEDDEV_CNT,LEDDEV_NAME);
    }
    else
    {
        alloc_chrdev_region(&leddev.devid,0,LEDDEV_CNT,LEDDEV_NAME);
        leddev.major = MAJOR(leddev.devid);
        leddev.minor = MINOR(leddev.devid);
    }

    leddev.cdev.owner = THIS_MODULE;
    cdev_init(&leddev.cdev,&led_fops);
    cdev_add(&leddev.cdev,leddev.devid,LEDDEV_CNT);

    leddev.class = class_create(THIS_MODULE,LEDDEV_NAME);
    if(IS_ERR(leddev.class)){
        return -PTR_ERR(leddev.class);
    }

    leddev.device = device_create(leddev.class,NULL,leddev.devid,NULL,LEDDEV_NAME);
    if(IS_ERR(leddev.device)){
        return PTR_ERR(leddev.device);
    }

    return 0;
}

static int led_remove(struct platform_device *dev)
{   
    iounmap(IMX6U_CCM_CCGR1);
    iounmap(SW_MUX_GPIO1_IO03);
    iounmap(SW_PAD_GPIO1_IO03);
    iounmap(GPIO1_DR);
    iounmap(GPIO1_GDIR);

    cdev_del(&leddev.cdev);
    unregister_chrdev_region(leddev.devid,LEDDEV_CNT);
    device_destroy(leddev.class,leddev.devid);
    class_destroy(leddev.class);
    return 0;
}

static struct platform_driver led_driver = {
    .driver = {
        .name = "imx6ul-led",
    },
    .probe = led_probe,
    .remove = led_remove,
};

static int __init leddriver_init(void)
{
    return platform_driver_register(&led_driver);
}

static void __exit leddriver_exit(void)
{
    platform_driver_unregister(&led_driver);
}


module_init(leddriver_init);
module_exit(leddriver_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("GARY");